1. Field of the Invention
The present invention relates to mobile communication devices and, more particularly, the present invention relates to mobile terminals communicating in a mobile IP network.
2. Related Art
The Internet, as we know it today, began as a joint project between the Department of Defense's (DoD's) Advanced Research Project Agency (ARPA) and the United Kingdom's National Physics Lab (NPL) during the height of the Cold War. When planning started in 1967, the project was conceived to distribute communications and data through a dispersed network of highly interconnected network nodes with high redundancy. A decision was made, based on research at the NPL, to move data through the network using a technique called “message switching”, or packet switching as it is called today. In order to exchange data, each node was assigned a unique address in relation to the addresses assigned to all other nodes. The address scheme devised was a 32-bit number comprising a network part and a host (network node) part. By 1971, 15 nodes, mostly at universities, were connected to the ARPA network (ARPANET). They were linked for time sharing to support a variety of remote terminals and allowed data transfers between distant computers.
The early 1970s produced a number of products that would effect the development of the ARPANET. The Palo Alto Research Center (PARC), funded by Xerox Corporation, developed a graphical user interface (GUI), a computer pointing device called a mouse, and most importantly, an Ethernet protocol, for inter-connecting computers that allowed users to send and receive electronic mail and share files.
At the same time that ARPANET was being develop for institutional use, the first personal computer was introduced by Altair in 1975. Sold as a kit, it was an instant success with computer enthusiast but its sales were limited due to the technical skill required to assemble the kit. It did, however, confirm that a market existed for a personal computer. Thus, in 1981, International Business Machines (IBM) introduced the Personal Computer (PC) which became the defacto industry standard. The IBM PC was an open architecture machine, meaning IBM published all technical details of the PC. This fact allowed low cost providers to produce PC “clones” so consumers were able to purchase personal computers at affordable prices. Low cost dial-up modems allowed PC users to download files from bulletin boards.
By the late 1980s, the ARPANET was almost 20 years old. The DoD split the ARPANET into two distinct parts for specific uses. One part was reserved for military sites (known as MILNET), while the ARPANET was for civilian use. Management of the ARPANET was turned over to the National Science Foundation (NSF) with NSF regional networks forming the backbone of the re-named Internet. Commercial Internet service providers (ISP) began offering Internet access points (AP) through which large numbers of PC users began accessing the Internet: These PCs were desktop machines whose location was not likely to change, thus creating a home network for ISP.
As technology evolved, smaller, more powerful laptop PCs became available. Their size released them from the desktop and the office. Sales, marketing, and technical personnel could take the laptop PCs on the road while maintaining contact with the office through remote applications such as e-mail and file transfers. These laptop PCs created mobile users that wanted to access the Internet while moving between networks, thereby causing a transition from a centralized system to a distributed system. Advances in wireless technology made wireless networking possible. Using a mobile IP protocol, laptop PCs, personal digital assistants (PDA) and mobile phones equipped for web browsing could access the Internet. Using either a static or dynamic mobile IP address assigned by their home networks, these mobile users or mobile terminals accessed the Internet from any available Internet access point.
When a mobile terminal changes its access point from its home network to a foreign network, it does not change its mobile IP address. Home agents (HA) are special servers responsible for routing data packets to absent mobile terminals. The HA is informed of the absent mobile terminal's location when the mobile terminal registers with the foreign network. The server on the foreign network, the foreign agent (FA), provides its IP address (care-of address) to the HA during mobile terminal registration. After registration, the FA is responsible for routing data packets between the mobile terminal and home network via the HA. A problem exists, however, in that not all data packets are destined for the home network. For example, data packets destined for a web server are routed to the HA causing the HA to forward them to the web server. A response from the web server is routed back to the HA which must then forward the data packets back to the FA. This routing and re-routing of data packets requires the home network provider to provision equipment and resources for network traffic that is not explicitly intended for the home network.
Accordingly, there is a need in a wireless data network for a method and apparatus to intelligently route mobile terminal data packets in a manner that is more efficient in terms of resource requirements and that reduces unnecessary network traffic.